Mouth-piece for speaking-tubes



(No Model.)

M. HEIDELMEIER.

MOUTH PIECE FOR SPEAKING TUBES. No. 280,374. Patented July 3, 1883.

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UNITED STATES PATENT OFFICE.

MAX HEIDELMEIER, OF CHICAGO, ILLINOIS.

MOUTH-PiECE FOR SPEAKING-TUBES.

SPECIFICATION forming part of Letters Patent No. 280,374, dated July 3, 1883.

Application filed April 28, 1883. (No model.)

To all whom it may concern:

Be it known that I, MAX HEIDELMEIER, of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful 5 Improvements in Mouth-Pieces for Speaking- Tubes, of which the following, in connection with the accompanying drawings, is a specification.

In the drawings, Figure 1 is a side elevation of a speaking-tube provided with my improved mouth-piece. Fig. 2 is a vertical central section thereof, and Fig. 3 is a top View of the mouth-piece.

Like letters of reference indicate like parts.

The call-whistle located in or near the mouthpiece of speaking-tubes has heretofore been pivoted or hinged so as to be capable of being turned away from the interior sides of the tube, or so as to leave the tube as nearly open as possible while it was being spoken through. The necessity of turning aside the call-whistle at the time and for the purpose referred to 'resulted from the fact that the whistle to a great extent obstructed the passage of the sound and rendered it comparatively indistinct. My pur: pose is to so construct the mouth-piece that a clear and distinct articulate sound may be c011- veyed through a call-tubewithout turning aside the call-whistle; and to that end my invention consists in certain novel features of construction, hereinafter set forth in my claims.

A represents an ordinary metallic speakingtube, and B is the mouth-piece. C is the callwhistle. D is a fly-piece or flap. to indicate the floor or story from which the call proceeds. That part of the mouth-piece which is immediately-in front of the call-whistle flares or expands, as shown at a, and is then drawn in or contracted, as shown at a; and a is a flan ing or expanding part constituting the end or external portion of the mouthpiece. I locate the whistle C at or near the inner end of the contracted part a, as shown, and attach it rigidly to the mouth-piece by soldering or otherwise, it being understood that the whistle may be constructed in the usual or in' any wellknown or suitable way.

I deem it best, but not absolutely essential, to apply the funnel-shaped part E to the rear or inner side of the whistle, the smaller end of the part E being toward the opening through the whistle, as shownv In other respects the speakingtube and mouth-piece may be constructed in the usual manner.

It will be perceived from the foregoing description, and from reference to the drawings, that there are no parts requiring any manipulation, excepting that the fiy-piece or flap D should be thrown or turned back from the mouth-piece after each call; but this flap is not essential when only one tube is employed, and does not constitute a feature of my i11- vention.

I find that in using a fixed whistle in a mouth-piece having an annular recess in front of the whistlesuch as formed by the junction of the oppositely-inclined parts a, and a'the message is delivered clearly and distinctly, although the whistle remains fixed across the interior of the tube. The mouth-piece expansion a aids in concentrating the sounds or messages delivered into the tube, and consequently delivers them more clearly therefrom. I also find that it is unnecessary to place either the mouth or the ear directly to the mouthpiece either in giving or receiving a message.

I am aware that the flap D and flaring expansion or part a are old and well-known in connection with speaking-tubes, and I do not therefore here intendeither to claim or be re stricted to the said parts, although I deem them desirable adjuncts to those features of construction which constitute my invention. The part E concentrates the current of air in giving the call, and also concentrates the sound.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. The combination, with the callwhistle of a speaking tube, of the bulging tubular part a and a, located in front of the whistle, sub stantially as and for the purposes specified.

2. The combination, with the call-whistle of a speaking tube, of the bulging tubular part a and a, located in front of the whistle, and the funnel-shaped part E, located behind the whistle, substantially as and for the purposes specified.

MAX HEIDELMEIER.

Witnesses:

F. F. WARNER, J. B. HALPENNY. 

